Rick , so have you or anyone looked at switch-off transients of the original switches? And also contact bounce on closing for other reasons?

Re some SSRs see

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pdf???? 3? -----??

Later they call for peak switching for transformers

don

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………….It appears that some experimentation could? in order.

If you have a dual trace scope, you can easily measure the input voltage & current on the transformer primary and observe the phase difference between the 2 in real time and during switching events………